Wedge type bolt or pin



J. V. HAMMOND WEDGE TYPE BOLT OR PIN Sept. 15, 1953 Filed June 25, 1951 INVENTOR cfo/uz KEG 1727720720? ATTORNEY-5 Patented Sept. 15, 1953 UNITED STATES PATENT OFFICE 1 Claim.

This invention relates to a wedge type bolt or pin and, more particularly to such a bolt for use in mining.

A primary object of the invention is the provision of a bolt or pin which may be inserted in a hole in the roof of a coal mine or the like for holding up rock or slate or other material having laminated strata.

An additional object of the invention is the provision of such a pin which, when inserted in the roof, will expand the full length of its associated bore to completely fill the same thus precluding the entrance of air into the hole to loose the rock or slate of the roof.

A further object of the invention is the provision of such a pin which will serve to tie various laminations or layers of slate together to preclude the falling of the lowermost layer.

Still other objects reside in the combinations of elements, arrangements of parts, and features of construction, all as will be more fully pointed out hereinafter, and shown in the accompanying drawing wherein there is disclosed a preferred embodiment of the inventive concept.

In the drawing:

Figure 1 i a fragmentary diagrammatic sectional view of a mine roof showing the bolt of the instant invention in position.

Figure 2 is an elevational view of the bolt.

Figure 3 is a sectional view taken substantially along the line 3-3 of Figure 2 as viewed in the direction indicated by the arrows.

Figure l is a sectional view taken substantially along the line 5-4 of Figure 2 as viewed in the direction indicated by the arrows.

Figure 5 is a sectional view taken substantially along the line 5-4) of Figure 2 as viewed in the direction indicated by the arrows.

Referring now to the drawings in detail, there is generally indicated at It the roof of a. coal mine or the like comprised of layers or strata ll of rock, slate, or similar material, and supported in the customary manner by spaced shoring I2. In the event that loose rock is located between shoring at a point such as l3 a bore M is drilled through the lower strata into one or more sueceeding strata, and the pin generally indicated at i5 of the instant invention driven thereinto, as will be more fully explained hereinafter.

Referring now to the pin in detail it is comprised of a cylindrical member It preferably comprised of wood or similar material of any desired useful length depending on the conditions of the particular mine in which it is adapted to be used. The member I5 is provided with two V- shaped grooves ii, the grooves being widest at opposite ends of the pin. Grooves El taper gradually to intersecting points, as best shown in Figures 3 and 5 which points are positioned at right angles to each other, each groove extending slightly past the center line of member it. A wedge l8 of a taper conforming to the taper of each groove IT is adapted to be inserted in each groove extending from opposite ends of member it. Each wedge is provided at its apex with a centrally positioned V-shaped slot, whereby the wedges when driven inwardly to their fullest extent may intersect at the apexes of the if-shaped grooves.

The use and operation of the device should now be readily understandable. The hole or bore it is first drilled to a depth slightly less than the length of the pin l5. The wedges ii are then inserted in their oppositely positioned grooves and the pin, which is of a diameter very slightly less than that of the bore, is inserted to its fullest extent therein, until the end of the uppermost wedge l8 abuts the top 2!} of bore it. Further driving, as by means of a sledge against the exposed end of the lower wedge will cause the wedges It to enter grooves ll to their fullest extent, thus expanding the member it completely to fill bore Hi throughout the entire length thereof to preclude the entrance of air into the bore and, consequently, into any cracks between the laminations or strata of the rock or slate, thus effectively preventing the fall of the material of the roof.

Due to the fact that the opposite ends of the \.'-shaped groove [7 will be expanded slightly more than the central portion of bolt is, it will also be apparent that the member serves effectively to pin the lowermost strata of the mine roof to adjacent strata.

It will be readily understandable that the pin of the instant invention is not intended to be utilized as a substitute for shoring within a mine, but is utilized in such places between the shoring as indicate the presence of loose rock or similar material.

As many embodiments may be made of this inventive concept and as many modifications may be made in the embodiment herein shown and described, it is to be understood that all matter herein is to be interpreted merely as illustrative and not in a limiting sense.

groove, said wedges being of substantially the configuration of said grooves and when fully inserted extending beyond the ends of said member, the total length of said wedges being greater than the length of said member, said grooves being at right angles to each other and intersecting at the mid point of said cylindrical member, each said wedges being provided With a centrally positioned V-shaped groove at its apex whereby when fully inserted they may intersect, the sides of said wedges being ar-cuate and having a radius of curvature conforming to that of said cylindrical member, driving of said wedges in the grooves of said member effecting expansion of said member substantially throughout the length thereof JOHN V.

References Cited in the file of this patent UNITED STATES PATENTS Number 0 Number Name Date Evans Apr. 29, 1913 Hauck May 20, 1924 Gothier Oct. 5, 1926 Oresenigo Aug. 27, 1929 Jensen -1 Feb. 5, 1935 FOREIGN PATENTS Country Date Switzerland Feb. 16, 1925 

